Michelle Obama calls herself a 'single mother'

In subsequent comments, the first lady said she sympathized with working moms who struggled with busy schedules.

“As a busy working mom, and before I was in the White House, I was in that position as well. Working, driving kids to practice, not having enough time to shop or cook. Not having the energy. Resources weren’t the issue, but time and energy is key,” Obama said.

On Thursday, the first lady was joined by about 30 children on the White House's South Lawn to plant wheat, spinach, potatoes, kale, radishes and other vegetables for the White House garden. It's the fifth year the first lady has planted the garden, intended to promote her healthy food initiative.